Failure: create EventGrid subscription for Azure Communication Service via yaml pipeline

Question

Failure: create EventGrid subscription for Azure Communication Service via yaml pipeline

Ben Joseph 0

We have a yaml pipeline that attempts to create an EventGrid event within our Azure Communication Service resource. That step of the pipeline fails with the error message below. We have retried the pipeline multiple times over the last 6+ hours.

ERROR: (Internal error) The operation failed due to an internal server error. The initial state of the impacted resources (if any) are restored. Please try again in few minutes. If error still persists, report d638156d-f63c-46ff-b6e4-7adc39ff6166:9/4/2026 12:38:15 PM (UTC) to our forums for assistance or raise a support ticket .

Code: Internal error

The yaml pipeline uses an AzureCli step with the following script (partially redacted):

az eventgrid event-subscription create --name "emaildeliveryreport" --source-resource-id "/subscriptions/.../resourceGroups/.../providers/Microsoft.Communication/CommunicationServices/..." --delivery-identity-endpoint-type servicebusqueue --delivery-identity systemassigned --delivery-identity-endpoint "/subscriptions/.../resourceGroups/.../providers/Microsoft.ServiceBus/namespaces/.../queues/tsi.notification.email.deliveryreport" --included-event-types "Microsoft.Communication.EmailDeliveryReportReceived"

0 comments

2 answers

Your answer

Answer 1

Ben Joseph 0

After waiting a few more days and re-trying the failed jobs of our pipeline, it worked. We didn't make any changes. It just started working a few days later.

Tejaswini Billakurthi 250 Reputation points Microsoft External Staff Moderator

2026-09-10T06:54:36.0433333+00:00

Hi @Ben Joseph ,

Thank you for the update. Good to hear the pipeline completed successfully without any configuration changes.

Given the internal server error and the fact that the same deployment succeeded on a later retry with nothing changed, this appears consistent with a transient service-side condition. Without backend diagnostic information, the exact root cause can't be confirmed.

If it happens again, retain the error's reference ID and UTC timestamp and raise an Azure support request so the service team can trace the corresponding backend operation.

If you feel the issue has been resolved, please consider marking the answer as accepted so that other community members experiencing similar intermittent failures can benefit from the troubleshooting guidance.

Answer 2

Hello @Ben Joseph

Thank you for reaching out to Microsoft Q & A!

Thank you for providing the error details.

The error returned by the az eventgrid event-subscription create command indicates that the request reached the service but failed with an internal server error during processing. Based on the information provided, it is difficult to determine whether the failure is related to the Event Grid service, the Azure Communication Service resource configuration, or the destination Service Bus configuration.

As initial validation steps, please verify the following:

Ensure that the Azure Communication Service has a system-assigned managed identity enabled.
Confirm that the managed identity has the appropriate permissions on the target Service Bus queue (for example, Azure Service Bus Data Sender).
Verify that the Service Bus queue exists and that no networking restrictions, firewalls, or private endpoint configurations are preventing access.
Review the Azure Activity Log for any additional error details related to the subscription creation request.
Run the command with the --debug parameter and check whether any additional information is returned.

Additionally, if possible, try creating an Event Grid subscription using a different endpoint type (such as a webhook) to determine whether the issue is specific to the Service Bus delivery endpoint.

Could you also confirm:

Whether the Azure Communication Service managed identity is enabled?
Whether the required RBAC permissions have been granted on the Service Bus queue?
Whether the same command has worked successfully in the past?

This information would help narrow down the root cause of the failure.Thank you for providing the error details.

Please "Upvote the Answer" if this information helped you. This will help us and others in the community as well.

Ben Joseph 0 Reputation points

2026-09-04T14:35:47.55+00:00

Thank you for the quick response. Here's what I've been able to find so far.

The Communication Service does not have a managed identity. But the Event Grid resource does have a system assigned identity, and it has Service Bus Data Sender permissions. Since Event Grid is the one that will put a message on the bus, that seems right to me.

The Service Bus queue exists and has worked great in the past.

A couple more points, just for clarification of our situation:

The error is happening in our production-level subscription. Therefore, I don't have permission to run the command with the --debug parameter. I also don't have permission to try creating a different kind of Event Grid subscription. If those are absolutely necessary things to try, I can try to find someone who either has permission to try those things, or who can grant me permission.

We run the pipeline every 2 weeks. It has been running successfully for more than a year. The last successful run in Production was 2 weeks ago. We haven't made any changes to the pipeline or the resources for quite a while. The only changes have been code changes in our API and Function Apps.

In case it helps to know: the same pipeline also runs in our Development and Test environments, which are very similar to the resources in Production (except in different Azure subscriptions). We use Terraform to create the resources, then the yaml pipeline to deploy code and do additional configuration. In the Development environment, the pipeline has successfully run multiple times within the last 24 hours.